Murphy-Erdosh C, Yoshida C K, Paradies N, Reichardt L F
Department of Physiology, University of California, San Francisco 94143-0724, USA.
J Cell Biol. 1995 Jun;129(5):1379-90. doi: 10.1083/jcb.129.5.1379.
The cadherin family of calcium-dependent cell adhesion molecules plays an important part in the organization of cell adhesion and tissue segregation during development. The expression pattern and the binding specificity of each cadherin are of principal importance for its role in morphogenesis. B-Cadherin and LCAM, two chicken cadherins, have similar, but not identical, spatial and temporal patterns of expression. To examine the possibility that they might bind to one another in a heterophilic manner, we generated, by cDNA transfection, L-cell lines that express LCAM or B-cadherin. We then examined the abilities of these cells to coaggregate with each other and with other cadherin-expressing cells in short-term aggregation assays. The B-cadherin- and the LCAM-expressing cell lines segregate from P-, N-, or R-cadherin-expressing cells. B-cadherin- and LCAM-expressing cell lines, however, appear to be completely miscible, forming large mixed aggregates. Chick B-cadherin and murine E-cadherin also form mixed aggregates, indistinguishable from homophilic aggregates. Murine E-cadherin and chick LCAM coaggregate less completely, suggesting that the heterophilic interactions of these two cell lines are weak relative to homophilic interactions. These data suggest that heterophilic interactions between B-cadherin and LCAM are important during avian morphogenesis and help identify the amino acids in the binding domain that determine cadherin specificity.
钙依赖性细胞黏附分子的钙黏蛋白家族在发育过程中的细胞黏附组织和组织分离中起着重要作用。每种钙黏蛋白的表达模式和结合特异性对其在形态发生中的作用至关重要。B-钙黏蛋白和LCAM是两种鸡钙黏蛋白，它们具有相似但不完全相同的时空表达模式。为了研究它们可能以异嗜性方式相互结合的可能性，我们通过cDNA转染产生了表达LCAM或B-钙黏蛋白的L细胞系。然后，我们在短期聚集试验中检测了这些细胞彼此之间以及与其他表达钙黏蛋白的细胞共同聚集的能力。表达B-钙黏蛋白和LCAM的细胞系与表达P-、N-或R-钙黏蛋白的细胞分离。然而，表达B-钙黏蛋白和LCAM的细胞系似乎完全可混溶，形成大的混合聚集体。鸡B-钙黏蛋白和小鼠E-钙黏蛋白也形成混合聚集体，与同嗜性聚集体无法区分。小鼠E-钙黏蛋白和鸡LCAM的共同聚集不太完全，这表明这两种细胞系的异嗜性相互作用相对于同嗜性相互作用较弱。这些数据表明，B-钙黏蛋白和LCAM之间的异嗜性相互作用在鸟类形态发生过程中很重要，并有助于确定结合域中决定钙黏蛋白特异性的氨基酸。
